In mammals, protein degradation is a continuing process on a rather large scale. The degradative process requires bioenergy and presumably occurs in the intracellular organelle, the lysosome. We have discovered an enzyme (ATPase) which is located in the lysosomal membrane and consumes bioenergy. We are pursuing the possibility that this enzyme is the direct link between degradation and bioenergy. As part of our long range goal of elucidating the mechanism of and regulation of degradation, we are purifying the enzyme. The pure enzyme will enable us to prepare specific inhibitors of the enzyme (antibodies) which will be used to probe its physiological function. BIBLIOGRAPHIC REFERENCES: Schneider, D.L. (1974). Biochem. Biophys. Res. Commun. 61, 882-888. A Membranous ATPase Unique to Lysosomes. Jacobs, J., Gerard, K., Schneider, D. (1976). Fed. Proc. abstracts (in press). A New, In Vivo Procedure for Localized Radiolabeling of Muscle Proteins.